Based upon years of study in Spanish archives, Professor Hamilton’s book attacks a problem not only of historical interest but of immediate economic importance. At a time when the relations between the gold supply and the price level are being anxiously watched, it is important to know how the price indices of commodities in general and of such groups as grains, building materials, fruits and nuts, poultry, animal products, forestry products, fish, and spices behaved under the impact of the greatest proportional increase in the stock of the precious metals in history. For the first time the Price Revolution, which vitally affected the economic life of Europe and was one of the most important factors in the decay of mediaeval economic institutions and the rise of modern capitalism, is studied in the country where it first appeared and presumably was most violent.